Title: GENERAL MEDICINE CONFERENCE
1GENERAL MEDICINE CONFERENCE
- HYPERTHYROIDISM
-
- Selim Krim, MD
- Assistant Professor
- Texas Tech University Health Sciences Center
2SIGNS AND SYMPTOMS
- Skin Increased Sweating and heat intolerance,
onycholysis, hyperpigmentation, pruritus and
thinning of the hair. - Eyes Stare and lid lag, exophtalmos if graves
disease - Cardiac Palpitations, exertional dyspnea,
anginal-like chest pain, tachycardia, atrial
fibrillation, CHF - GI Weight loss, diarrhea
- Neuro-psych Anxiety, restlessness, irritability,
emotional lability, psychosis, agitation, and
depression - Metabolic/Endocrine Hyperglycemia, low serum
total and high-density lipoprotein (HDL)
cholesterol
3GRAVES DISEASE
- Signs and symptoms of hyperthyroidism
- Exopthalmos, proptosis, lid lag, orbital edema
-
- Diffuse goiter
- TSH receptor antibodies
- Increased RAI uptake
4MUST KNOW
- T4 and T3 are produced in thyroid gland but T3 is
the active component. - T3 can also come form T4.
- T4-to-T3 conversion is stopped by starvation,
liver disease and certain drugs
(propylthiouracil, propranolol, prednisone) - T4 and T3 are circulating as bound proteins-TBG
(thyroid binding globulin) - If TBG goes up-T4 and T3 would go up. If TBG goes
down-T4 and T3 would go down.
5GENERAL RULE
- Hyperthyroidism with a high radioiodine uptake
indicates de novo synthesis of hormone. - Hyperthyroidism with a low radioiodine uptake
indicates either inflammation and destruction of
thyroid tissue with release of preformed hormone
into the circulation, or an extrathyroidal source
of thyroid hormone.
6FACTITIOUS VS. SUBACUTE THYROIDITIS
FACTITIOUS HYPERTHYROIDISM SUBACUTE THYROIDITIS
THYROID GLAND Painless gland Painful gland
SERUM THYROGLOBULIN Low/Normal High
SEDIMENTATION RATE Normal High
7DIFFERENTIATING THE THREE TYPES OF THYROIDITIS
Subacute thyroiditis/Viral thyroiditis/de Quervains thyroiditis Silent or painless thyroiditis (Chronic lymphocytic) Hashimotos thyroiditis (Painless goiter)
Viral Idiopathic mainly in women, typically 3-12 months after pregnancy (Postpartum thyroiditis) Autoimmune. Multinodular goiter is the outstanding feature.
High ESR with fever Normal ESR High or normal ESR
High T4 and T3 early on-later low T4 and T3. Low RAIU Anti-thyroglobulin antibodies are usually elevated. TPO antibodies usually normal. High T4 and T3 with low TSH initially, then Low RAIU, low T4 and T3. Anti-thyroglobulin antibodies may or may not be elevated. TPO elevated in 75 of cases. Initially eu, hyper- or hypo, eventually hypothyroid. Low RAIU. Anti-thyroglobulin antibodies are present in 85 of cases. TPO in 95 of cases.
Aspirin/Steroids Beta-blockers if needed Levothyroxine if needed
8INDICATIONS FOR SURGERY
- Patients with very large goiters
- Goiters causing upper airway obstruction or
severe dysphagia - In a patient who also has a nonfunctional thyroid
nodule, which can be a thyroid cancer, surgery
can both cure the hyperthyroidism and remove the
nodule. - Moderate to severe Graves' ophthalmopathy,
- Pregnant women who are allergic to antithyroid
drugs and/or are tolerating hyperthyroidism
poorly
9Case 1
- A 27-year-old woman is evaluated for
palpitations and heat intolerance that develop 3
months after a successful pregnancy. She is
breastfeeding. The patient's older sister has
Graves' disease, but the patient herself has no
history of thyroid disease. On physical
examination, the blood pressure is 128/70 mm Hg,
and the pulse rate is 104/min. Eye examination
reveals stare and lid lag, but no proptosis. The
thyroid gland is moderately enlarged and
nontender. She has moist palms and brisk deep
tendon reflexes. Serum free T4 is 2.7 ng/dL (34.2
pmol/L), free T3 46.22 ng/dL (7.1 pmol/L), and
thyroid-stimulating hormone (TSH) is
undetectable. Which one of the following is the
most appropriate next step in this patient's
management? - A- Serum anti-thyroid peroxidase
antibodies - B- Serum thyroglobulin level
- C- Serum TSH immunoglobulins
- D- An empiric trial of antithyroid drugs
- E- Radioiodine (I-131) uptake and thyroid
scan
10Case 2
- A 27-year-old male athlete is evaluated for
frontal headache, palpitations, and heat
intolerance and an elevated serum
thyroid-stimulating hormone (TSH) level. On
physical examination, the blood pressure is
147/78 mm Hg, a pulse rate of 88/min, and a
mildly enlarged thyroid gland. He has a fine
tremor, moist palms, and deep tendon reflexes are
brisk. On laboratory testing, serum free T4 is
2.9 ng/dL (38.0 pmol/L) and TSH is 6.8 µU/mL (6.8
mU/L). Antithyroid peroxidase and
antithyroglobulin antibodies are negative. Which
of the following is the most appropriate next
test in the evaluation of this patient? - A- MRI of the pituitary
- B- Thyroid function testing of family
members - C- Radioactive iodine uptake and thyroid
scan - D- Serum thyroglobulin level
- E- Thyroid stimulating immunoglobulins
11Case 3
- 65-year-old man with refractory atrial
fibrillation begins therapy with amiodarone.
Baseline thyroid hormone levels are normal. One
month later, the patient is asymptomatic but has
the following laboratory findings total T4, 13.4
µg/dL (172.46 nmol/L) free T4, 2.7 ng/dL (34.2
pmol/L) free T3, 11.72 ng/dL (1.8 nmol/L) TSH,
3.9 µU/mL (3.9 mU/L). Which of the following is
the most likely explanation for these findings? - A- Amiodarone-induced thyroiditis
- B- Iodine-induced hyperthyroidism
- C- Expected changes in euthyroid patients
taking amiodarone - D- Spurious laboratory results caused by
amiodarone - E- Euthyroid sick syndrome
12Case 4
- A 24-year-old woman is evaluated for
palpitations and sweating that began 4 weeks
after she delivered her first child 8 weeks ago.
She has had occasional loose stools. Otherwise,
she has felt generally well. She nursed her baby
for 6 weeks but decided to stop 2 weeks ago. Her
family history is unremarkable. She is taking
multivitamins but no other supplements. On
physical examination, the blood pressure is
110/60 mm Hg, pulse rate 92/min, and BMI 23.7.
The thyroid gland is normal size, slightly firm
in consistency, and nontender. Thyroid-stimulating
hormonelt0.01µU/mL, free T43.4ng/dL, total
T3315ng/dL, radioiodine uptakelt1. Thyroid scan
not visualized. Which of the following is the
most appropriate therapy for this patient? -
- A- Radioactive iodine (I-131)
- B- Ăź-Blocker
- C- Prednisone
- D- Propylthiouracil
- E- Aspirin
13Case 5
- A 59-year-old woman is evaluated for a
2-week history of diffuse arthralgias, malaise,
anorexia, and left-sided neck pain and swelling.
The pain radiates upwards towards the left ear.
She has no fever, chills, palpitations, or
nervousness. On physical examination, the
temperature is 37.3 C (99.2 F), and the pulse
rate is 92/min. Thyroid examination shows warmth,
tenderness, and moderate enlargement of the left
lobe of the gland, without fluctuance. Laboratory
testing shows a leukocyte count of 12,300/µL
(12.3 109/L), with 82 segmented cells and 3
bands erythrocyte sedimentation rate is 113
mm/h. Serum free T4 is 3.0 ng/dL (38.6 pmol/L),
and TSH is 0.04 µU/mL (0.04 mU/L). CT scan of the
neck shows no evidence of abscess. Which of the
following is the most appropriate therapy at this
time? - A- Propylthiouracil 100 mg three times daily
- B- Radioiodine ablation therapy
- C- Thyroidectomy
- D- Systemic antibiotic therapy
- E- Prednisone 40 mg once daily
14Case 6
- A young female has weight loss,
irritability, diarrhea, very high T4, low TSH,
and a low RAIU. O/E thyroid gland is painless.
Serum thyroglobulin level is low. TPO antibodies
are normal. What is your diagnosis? - A- Graves disease.
- B- Subacute thyroiditis.
- C- Chronic lymphocytic thyroiditis
- D- Factitious hyperthyroidism
- E- Hashimotos thyroiditis.
15Case 7
- A 33 year old female gave birth to a healthy
child 6 weeks ago. She complains of tremors and
anxiety. T4 is elevated while TSH is low normal.
In addition to prescribing beta-blockers, which
of the following would you order to confirm your
diagnosis? - A- Lugol iodine
- B- Radioactive iodine
- C- RAU uptake
- D- Observation
16Case 8
- A 32 year old, 4 months post-partum nurse
comes to you for depression. O/E thyroid is
enlarged but painless to palpation. Blood tests
reveal high T3 and low TSH. What is your next
step in the management of this patient? - A- Free T4
- B- RAI uptake
- C- A trial of propylthiouracil
- D- Propranolol
- E- Observation
17Case 9
- 2 months later she comes back with continued
symptoms of depression. The previously ordered
RAIU was low. Blood tests now reveal low T3 and
high TSH. What is your next step in the
management of this patient? - A- No medication, reassurance, and to return
for rechecking thyroid function test in 3 months - B- Give synthroid for short term and
reassure that she will be fine soon - C- refer her to a psychiatrist
- D- Check for spurious intake of thyroid
hormone
18